Such a converter circuit is disclosed in German patent application No. 2,205,193 which has been laid open to public inspection, and is used as an adaptor for a TV receiver to enable TV signals which are outside the standard TV frequency range to be displayed. When using this known circuit the tuning section of the TV receiver is fixedly adjusted to a given TV channel. Selection and conversion of a desired TV signal, which is possibly located outside the standard TV frequency range, to the channel to which the TV receiver has been tuned is effected in the converter circuit. The tuning is varied by operating the converter circuit.
The use of this known converter circuit results in a change in the manner of tuning with which the user must be acquainted. In addition, when the user has a TV receiver with remote control, this convenient feature is lost and he is compelled to operate the converter circuit to tune his TV receiver.